1. Field of the Invention
The present invention generally relates to a transmission line, in particular to low cross-talk differential microstrip lines for high-frequency signal transmission.
2. Description of the Related Art
In recently years, since signal transmission rates become higher, and the size of electronic products becomes smaller, electronic circuits tend to be designed to be denser. Thus, the cross-talk between electronic circuits becomes serious. When signals are transmitted via transmission lines, the adjacent transmission lines will be interfered by each other due to the electromagnetic wave coupling phenomenon; as a result, the interfered transmission lines may generate coupling voltage and current, which is so-called cross-talk. Excessive cross-talk may influence the efficiency of the system; further, some components of the system may be triggered by accident, which may damage the system. Besides, when parts of an electronic circuit should be designed to be bent, engineers usually increase the interval between the adjacent microstrip lines, or increase the rising and falling time of the digital signals to reduce the cross-talk; however, the cross-talk still cannot be completely eliminated.
As the conventional methods cannot effectively eliminate the cross-talk occurring between transmission lines, it is necessary to propose novel differential microstrip lines with low cross-talk for high-frequency signal transmission for the purpose of suppressing the cross-talk and reducing the mode conversion effect between the differential mode and the common mode.